Posts Tagged ‘aquatic ecology’

Recently, my daughter participated in Odyssey of the Mind, a creative problem solving competition devoted to ingenuity and team work. As an entomologist, I was thrilled to learn that the program calls its highest award the Ranatra fusca. Not only was the award named for an insect, but an aquatic insect, and a particularly fascinating one to boot.

Ranatra fusca is the Latin name for a water scorpion, a creature little known to the general public but familiar to those of us who wield nets in ponds. This insect bears only a passing resemblance to real scorpions (which are arachnids, not insects). It does sport what looks like a prominent tail (more about that later), but lacks any sort of stinger. It can, however, be quite lethal… if you happen to be an aquatic insect, tadpole, or even a small fish. » Continue Reading.

In peaceful streams, aquatic macroinvertebrates such as crayfish, stoneflies, and caddisflies travel over and under submerged rocks, foraging for other invertebrates, leaves, and algae. When rain falls, their world turns upside down. At first only the surface is disturbed, but before long, runoff reaches the stream and increases its flow many fold. Silt and sand blast every exposed rock surface. At peak flow, boulders are propelled downstream by powerful currents.

How do small creatures survive such crushing chaos? They hunker down. Water-filled nooks and crannies extend deep below streambeds and far beyond river banks. These deep interstices provide a safe haven even while turbulent water pulverizes the riverbed, comparable to a storm cellar in a tornado. » Continue Reading.

The Adirondack Park’s trout and salmon fishing would likely disappear by 2100 without global action to counteract climate warming according to a new report by the U.S. Environmental Protection Agency (EPA). EPA’s study concludes global action to reduce greenhouse gas emissions would save 70 percent of Adirondack trout and salmon from extinction. The EPA report also predicts widespread damage to other cold-water fisheries, public health, clean water, electricity grids, roads and bridges, forestry, agriculture and coastal communities.

The EPA’s report is titled Climate Change in the U.S.: Benefits of Global Action is a summary of the Climate Change Impacts and Risks Analysis (CIRA) project, a peer-reviewed study. It compares impacts in a future with significant global action on climate change to a future in which current greenhouse gas emissions continue to rise. » Continue Reading.

Since the retreat of the glaciers, lake trout (Salvelinus namaycush) have been the top native predator in Adirondack waters. These northern fish require true cold (less than 55°F) and move downward when surface waters warm in late spring and summer. Consequently, they are isolated to the largest and deepest Adirondack lakes – most of them deeper than 30 feet – where they stay in the dark chilly depths all summer and early fall. The species name namaycush is believed to be an Algonquin term for “dweller of the deep.”

This need for very cold, clean, high-oxygen water can bring to light otherwise invisible changes beneath the surface. Water quality in the Adirondack interior, where we don’t have much industry or farming, can be abstract. You usually can’t see it, touch it or even taste it. But lake trout make the health of our coldest lakes real and tangible. » Continue Reading.

Zebra Mussels and Asian clams receive so much attention that little is left for Lake George’s native mussels, which are as beneficial to the lake as the invasives are destructive.

Increasing awareness of the natives’ value and the potential threats to their survival is a mission of Dr. Dan Marelli, a Florida biologist whose expertise has made him a valued collaborator of the Darrin Fresh Water Institute whenever mollusks enter the picture.

In August 2010, for example, the first Asian clams discovered in the lake were immediately sent to him. He confirmed their identity, and the multi-million dollar effort to eradicate the invasive, or at least to contain its spread, began. When Zebra mussels were discovered in 1999, Marelli was among those who participated in a successful hand-harvesting eradication effort. » Continue Reading.

Following the July 4th weekend, there typically occur stretches of pleasant, sunny weather with highs in the 80’s. This elevates the temperature of the water in the many aquatic settings throughout the Adirondacks to their highest levels of the year and creates conditions ideal for swimming and for our warm water fishes.

Among the residents of lakes and rivers that thrive when the water becomes suitable for wading, lounging, and frolicking are the sunfish, and along the rocky shores of our glacially formed lakes and boulder laden waterways is the rock bass, a ubiquitous and always hungry fish that has frequent encounters with any novice angler that fishes these sites. » Continue Reading.

As the summer boating and tourism season begins, advocates for local lakes and rivers are calling on state lawmakers to make a major new commitment to fighting the spread of invasive species that are already impacting the lakes, rivers and forests of the Adirondack Park and beyond.

Proposed legislation (A. 7273/S. 9619) aims to prevent the spread of aquatic invasive species (AIS) by requiring the removal of visible vegetation and animals from boats as well as removing all areas of standing water in the engine, hulls, and live wells, when using any public or private boat launching facility in New York. This legislation prohibits the launching of boats that have any visible plant and animal matter on any surface of the boat or trailer or contains any standing water. Boats should be clean, drained and dry. » Continue Reading.

With this winter shaping up to be a cold one, spring may still seem far away. But with time and a little patience, we will soon start to notice the lilac leaves bursting from buds, the return of brightly colored warblers, and the ringing chorus of spring peepers in the evening. Any time you detect events unfolding in the natural world, you are making phenological observations.

Phenology refers to the study of the timing of biological activities. Perhaps unsurprisingly, many of these changes in the life cycles of plants and animals coincide with the seasons. Besides day length, factors that influence the timing of biological events include temperature, precipitation, snowpack formation and melting, and wind. » Continue Reading.

As cold weather becomes more common and intense, the temperature of lakes, ponds and marshes drop significantly, with ice soon appearing over the surface of our smaller and more shallow waterways. As these aquatic settings continue to relinquish heat to the atmosphere, most of their resident, cold-blooded creatures are forced by the low temperatures to become extremely lethargic or lapse into a dormant state until spring.

There are, however, a few forms of life that remain active throughout the winter, as these entities are well adapted for an existence in frigid waters. Among the animals that thrive in northern lakes, even during winter, is the lake trout, a sizeable predator that resides only in our largest and deepest lakes; and it is during mid to late autumn when this prized game fish migrates to certain gravel bottom locations in order to spawn. » Continue Reading.

As the water warms in streams, rivers and lakes, there is an explosion of invertebrate activity, when the hoards of aquatic bugs that pass much of the year on the bottom are stimulated by the favorable thermal conditions which allow them to continue with their life cycle. Among the insects preparing to leave the safety of some protective nook, or transition into a stage that no longer perfectly matches the surroundings, are the mayflies, an exceptionally prolific and ecologically significant group of aquatic organisms.

Mayflies form a category, or order, of insects known as Ephemeroptera, which literally translates into the short-lived insects. This label is somewhat a misnomer, as most mayflies have a life span of one full year. Nearly this entire period, however, is spent underwater, initially in the embryonic form of an egg and then as a naiad passing from one nymph stage into another as they consume and convert microscopic matter in the water into body tissue. » Continue Reading.